Smoke evacuation system

ABSTRACT

Smoke evacuation system for removal of aerosolized chemical compounds and biological fine particles produced during laser treatment of tissue. The rapid smoke evacuation is achieved by coupling a low capacity vacuum pump to a vacuum valve and a vacuum reservoir to create very high flow rate for very short durations. The opening time of the valve could at least partially overlap the laser pulse duration.

TECHNOLOGY FIELD

Air evacuation system for removal of aerosolized chemical compounds andbiological fine particles produced during laser treatment of tissue.

BACKGROUND

The laser devices that are used for skin treatment and in particular forhair removal, pigmented spots removal, skin ablation and other skintreatment procedures performed by application of localized extreme heatcause plumes of smoke to arise as intense heat is applied to flesh. Ithas been shown that this smoke, also known as laser plume in laserapplications and diathermy smoke in electrocautery applications,contains compounds that are potentially harmful to the health of thepersonnel participating in the operation. The smoke plume also containsultrafine particulate by-products, particles that are less than 1μ(micron) in diameter, which are undesirable because of the odor, theability to bypass natural filters and reach the deep alveolar space, andtheir potential carcinogenic properties.

Current approach to eliminate these by-products and the unpleasant odorcaused by the laser plume is the use of so-called smoke extractiondevices. Such devices usually include a pump, an external highefficiency particulate air (HEPA) filter attached to a hose, which isheld in proximity to the area of laser beam operation. The devicesoperate continuously and require evacuation of high volumes of air. Useof such devices is sub-optimal owing to the need of either a secondoperator to hold and maneuver the filter hose or the primary operator tomaneuver both the laser delivery device and evacuator hose, and theinconvenience of the large diameter hose that frequently needs to beapplied to a small skin area. Evacuation of high volumes of air requiresuse of large and noisy vacuum pumps which need to be run continuously togenerate the high air flow rates required for effective removal of theundesirable by-products.

The following US Patents and Patent Application Publications describedifferent apparatuses and methods of smoke extractions U.S. Pat. Nos.5,336,218, 5,575,789, 5,768,740, 5,908,403, 8,641,488, 2016/0193635 andPatent Cooperation Treaty Publications WO1997/014364A1, WO1998/004200A1.

SUMMARY List of Drawings and their Brief Description

FIG. 1 is a schematic illustration of a smoke evacuation or extractionsystem according to an example;

FIG. 1A is a schematic illustration of a smoke evacuation or extractionsystem similar to FIG. 1 but with a smoke filter located in conduit;

FIGS. 2A and 2B are schematic illustrations of a sleeve of a smokeevacuation system according to an example; and

FIGS. 3A and 3B are timing diagrams illustrating synchronous operationof some of the system of FIG. 1 elements.

DESCRIPTION

This current disclosure suggests resolving the smoke and particulateby-products problem by integrating a pulsed smoke evacuator andfiltration elements into one or more of elements of a skin treatmentsystem. In some examples, more than one smoke filtration elements couldbe incorporated into the system. The pulsed smoke evacuation could beachieved by coupling a low capacity vacuum pump to a vacuum valve and areservoir to create very high flow rate for very short durations. Theair flow could begin prior to the application of a laser energy pulse tothe skin, concurrently with the application of the laser energy pulseand continue after the application of the laser energy pulse. The highflow rates occur at a relatively low duty cycle by opening/closing ofthe vacuum valve and use of reduced air pressure in the reservoir.Operation of the vacuum valve is synchronized with the treatment laserand in particular with the laser trigger. Before being exhausted fromthe vacuum pump, the evacuated smoke and particulate by-products couldbe passed through a liquid, which could be a solvent or a combination ofsolvents that would facilitate almost complete extraction of the smokeand undesirable laser skin treatment by-products, including smallnoxious gas molecules and aerosolized organic compounds. Specificcompounds such as dimethyl sulfide and trimethyl sulfate have beenpreviously reported by Chuang et al. (JAMA Dermatology 2016; 152(12):1320-1326) which is included here in total as reference. The smoke couldbe passed through one or more particle filters to remove largerparticulates in the smoke, and/or subsequently could be passed through aliquid which will dissolve harmful chemical constituents of the smoke.

Laser trigger can include the release of a cryogen spray cooling skinprior to the firing of the laser and may even include a post lasercryogen spray for additional skin cooling. Operation of the vacuum valveis synchronized to open after the delivery of the cryogen spray butprior to or subsequent with the firing of the treatment laser. Inaddition vacuum valve is synchronized to close prior to the start of thepost-laser cryogen spray.

FIG. 1 is a schematic illustration of a smoke evacuation or extractionsystem according to an example. System 100 includes a laser 104 and alaser handpiece 108. Laser handpiece 108 is terminated by a sleeve 110configurable for application to a patient skin 114. Laser handpiece 108is receiving laser energy from laser 104. The smoke evacuation orextraction system also includes a vacuum pump 112 and a reservoir 116containing air at a reduced (negative) pressure. Reservoir 116 through aconduit 120 is in fluid communication with a smoke filter 136 shownassociated with laser handpiece 108. In order to reduce noise in thetreatment room, vacuum pump 112 could be located remote from laserhandpiece 108.

A high speed electrically controlled valve 124 is inserted into conduit120 and is operative to open and close the fluid communication betweensleeve 110 and vacuum reservoir 116. System 100 further includes aprocessor 128. Processor 128 controls and synchronizes operation ofsystem 100 and in particular the operation of high speed electricallycontrolled valve 124 and the operation of laser 104.

Smoke filter 136 could be a HEPA filter commonly found in clean roomsand air conditioning systems designed to filter particulates. Smokefilter 136 could include carbon activated air filters for removingvolatile organic compounds and odors. Pellets, flocked honeycomb,V-shaped cells of flocked honeycomb, and bonded flocked carbon panelsare examples of carbon activated air filters. Smoke filter 136 could bea liquid-phased filter 152 such as water for removing very fineparticulates. U.S. Pat. No. 5,908,493 is given here as reference. Otherliquids based on their solubility could be used as the filteringmaterial to reduce specific components that are soluble in the liquid.Specific malodor components can include hydrogen sulfide, dimethylsulfide, and trimethyl sulfate. Smoke filter 136 could be a combinationof two or more of a particulate filter, activated carbon filter, orliquid filter.

Smoke filter 136 of smoke evacuation or extraction system 100 isconfigured to filter smoke and particulate by-products generated by skintreatment procedures. In one example smoke filter 136 (FIG. 1) isintegrated with laser handpiece 108. In another example smoke filter 136could be located in conduit 120 (FIG. 1A) or vacuum reservoir 116.Tubing 132 supporting fluid communication between sleeve 110 and smokefilter 136 could be a flexible tubing facilitating easy operation andtranslation of laser handpiece 108. Tubing 132 supporting fluidcommunication between sleeve 110 and smoke filter 136 could bepositioned internally or externally relative to the shell of thehandpiece. Tubing 132 supporting fluid communication between sleeve 110and smoke filter 136 could be integrated as a hollow chamber within theshell of the handpiece.

Smoke filter 136 could be integrated with a particle filter 156 locatedin reservoir 116. Smoke filter 136 could be a replaceable and disposablefilter. Smoke filter 136 could also be integrated into sleeve 110 andboth smoke filter 136 and sleeve 110 could be replaceable anddisposable. Smoke filter 136 can also be designed to prevent or reduceloss of fluid 152 via air evacuation through the reservoir 116.Reservoir 116 containing one or more of particle filter 136 and solvent152 could be designed to be replaceable and disposable. For examplefluid 152, such as a solvent could also serve as a smoke filter. In oneexample, a complete air (vacuum) reservoir 116 including smoke andparticle filter 156 could be implemented as a user replaceable anddisposable element. Such combined vacuum reservoir and smoke filter,represent a single part/element that serves the function of holding anegative (reduced) air pressure (vacuum) as well as filtering odors,viruses, and other particulates from the air that is drawn in reservoir116 due to the vacuum.

A system activation switch 140 incorporated into handpiece 108 activateslaser 104 and smoke evacuation or extraction system 100. In someexamples, system 100 activation switch could be a footswitch. Generally,system 100 activation switch could be associated with any unit/elementof system 100.

FIGS. 2A and 2B are schematic illustrations of a sleeve of a laserhandpiece of a smoke evacuation system according to an example. As shownabove, sleeve 110 is associated with laser handpiece 108. In oneexample, sleeve 110 could be a disposable rigid sleeve made of abiologically compatible plastic material (FIG. 2A). In another example,sleeve 204 could be a flexible sleeve, for example a bellow (FIG. 2B).In both cases the sleeve (110 and 204) may be terminated by a type ofgasket or O-ring 208 that could be made of silicone or material similarto the sleeve material. Gasket or O-ring 208 supports air tightapplication of laser handpiece 108 on any surface and in particular onthe surface of the skin. The opposite end of sleeve 110 or 204 is alsoterminated by a gasket or O-ring 212 forming an air tight connectionwith laser handpiece 108. When applied to skin 114 (FIG. 1) the sleeveforms a confined/vacant volume. For typical laser skin treatments, theconfined/vacant volume could be cylindric in shape having a diameter of2 inches and a length of 2 inches, roughly 0.1 cubic decimeter. Smallvolumes can also be envisioned such as a 1 inch diameter and a 1 inchlength or roughly 0.01 cubic decimeter. Other shapes besides cylindricalwith similar volumes are envisioned. Sleeve 110 and 204 could be usedwithout a gasket or O-ring 208 including allowing laser skin treatmentwhile hovering close to the treatment surface but without touching theskin surface.

Whether using sleeve 110 or 204 with or without a gasket 208, sleeve 110or 204 may include well placed inlets to allow an inflow of air duringthe pulsed evacuation procedure. The cross-section of the one or moreinlets is designed to be big enough so as to not impede air flow. Theinlets could be one or more cut channels placed at the distal end ofsleeve 110 or 204. The inlets may be more complex and placed in aspecific pattern and may be finned so as to allow a vortex of air flowwithin the confined/vacant volume moving contaminated air away fromcentral portion axial to the laser beam. U.S. Pat. No. 5,768,740 isincorporated by reference in its entirety herein.

The vacant volume of sleeves 110 or 204 is small and the smoke andparticulate by-products generated by the skin treatment procedures couldbe easy evacuated by a low capacity flow rates in the range of 0.5 to1000 Ipm, or flow rate between 0.5 and 100 Ipm, or more specifically 0.5to 50 Ipm.

Sleeve 110 or 204 including gaskets 208 and 212 could be a disposablesleeve. Such sleeve could be disposed after each use. Accordingly,sleeve 110 or 204 could be made as an easy removable and exchangeablesleeve.

In one example (FIG. 2A), handpiece 108 includes a channel 216conducting smoke and particulate by-products from sleeve 110 or 204 to asmoke filter 136. In another example, the smoke and particulateby-products could be conducted from sleeve 110 or 204 to a smoke filterby relative to the handpiece shell an external or internal tubing 132.

To support rapid evacuation of the smoke and particulate by-productsgenerated by the skin treatment procedures and still use a small vacuumpump 112, pump 112 evacuates air from vacuum reservoir 116 and maintainslow level or reduced pressure in reservoir 116. The volume of vacuumreservoir 116 is made at least 2 times larger than the air volumeconfined in the sleeve. In some examples the volume of vacuum reservoiris made at least 20 times or even 100 times larger than the volume ofsleeves 110 or 204.

When high speed electrically controlled valve 124 opens the small volumeof sleeves 110 and/or 204, containing smoke and particulate products orparticles generated by the skin treatment procedures treatment is almostinstantly evacuated into reservoir 116 and from there is furtherevacuated by vacuum pump 112. Accordingly, the combination of a largevacuum reservoir and a low capacity vacuum pump 112 could still providehigh instantaneous flow rates sufficient for evacuation of skintreatment smoke and by products.

FIGS. 3A and 3B are timing diagrams illustrating synchronous operationof some of the system of FIG. 1 elements. In one example (FIG. 3A)processor 128 synchronizes operation of system 100 such that high speedelectrically controlled valve 124 opens and closes communication betweensleeve 110 (204) and reservoir 116, as shown by open/close pulses 308,synchronously with the operation of laser 104 emitting laser energypulses 304. High speed electrically controlled valve 124 also could opencommunication between sleeve 110 (204) and reservoir 116 just prior tothe start of the laser pulse and close communication between the sleeveand the reservoir just after the end of the laser pulse.

In another example (FIG. 3B) operation of high speed electricallycontrolled valve 124 opens and closes asynchronously with the operationof laser 104 emitting laser energy pulses 304. High speed electricallycontrolled valve 124 could open 312 before laser pulse 304-1 and closewith the termination of laser pulse 304-1; valve 124 could open 316before laser pulse 304-2, continue during the length of the pulse andclose some time after the termination of laser pulse 304-2; valve 124could open 320 synchronous with laser pulse 304-3, continue the lengthof the pulse and close some time after the termination of laser pulse304-3.

The laser pulse duration depends on a particular skin treatmentprocedure that the caregiver performs and could vary from 1 microsecondto 100 millisecond or more. Some skin treatment procedures are performedby a scanning laser beam. Although the laser beam is scanned along thetreated skin segment, the laser energy is typically delivered to theskin in pulse mode. The smoke evacuation system described above andmethod for smoke evacuation is also applicable to such quasi-continuouslaser operation.

The smoke and particles generated by the skin treatment proceduresevacuation system can be combined with different ablative andnon-ablative laser skin treatment products. The smoke and particulateby-products system reduces the cost of the equipment and noise producedby the vacuum pumps and improves skin treatment procedures environment.

What is claimed is:
 1. A rapid pulsatile smoke extraction systemcomprising: a laser handpiece terminated by a sleeve configurable forapplication to a patient skin; a laser providing laser energy to thelaser handpiece; a reservoir containing air at vacuum pressure, thereservoir is in fluid communication with the sleeve; a valve configuredto open and close communication between the sleeve and the reservoir;and a processor configurable to control operation of at least the valve,wherein operation of the valve is synchronized with the operation of thelaser, and wherein the valve opens communication between the sleeve andthe reservoir just prior to start of a laser pulse and closescommunication between the sleeve and the reservoir just after end of alaser pulse.
 2. The system of claim 1 wherein the sleeve is a removablesleeve and a disposable sleeve.
 3. The system of claim 1 wherein thesleeve when applied to skin forms a volume in communication with thereservoir for evacuation of the smoke.
 4. The system of claim 1 whereinthe sleeve is one of a group of sleeves consisting of a rigid sleeve anda flexible sleeve.
 5. The system of claim 1 further including a vacuumpump configured to generate the vacuum pressure in at least thereservoir.
 6. The system of claim 5 wherein the vacuum pump has a flowcapacity of 0.5 liters per minute to 1000 liters per minute.
 7. Thesystem of claim 5 wherein the vacuum pump has a flow capacity 0.5 litersper minute to 50 liters per minute.
 8. The system of claim 1 furthercomprising a smoke filter configured to filter smoke and particlesgenerated by skin treatment procedures.
 9. The system of claim 8 whereinthe smoke filter is at least one of a group of filters consisting of afilter integrated with laser handpiece, integrated into a reservoir,integrated into a conduit conducting smoke from a sleeve to a reservoir,and integrated directly into the sleeve.
 10. The system of claim 8,wherein the smoke filter is integrated directly into the sleeve.
 11. Thesystem of claim 10, wherein the reservoir includes a smoke andparticulate by-products filter, the reservoir connected by a tubing to avacuum pump.
 12. The system of claim 11, wherein the smoke andparticulate by-products filter includes a fluid and wherein the fluid isa solvent.
 13. The system of claim 1 wherein volume of the reservoircontaining air at a reduced pressure is at least twice larger than thevolume of the sleeve.
 14. The system of claim 1 wherein the systemincludes an activation switch.
 15. The system of claim 1 wherein thehandpiece includes a channel conducting smoke from the sleeve to atleast a smoke filter.
 16. A rapid pulsatile smoke extraction smokeevacuation system for skin treatment, comprising: a laser handpiece anda laser providing laser energy to the handpiece; a vacuum reservoir anda valve connecting between the vacuum reservoir and the laser handpiece;and a processor configured to synchronize operation of the laser and thevalve such that each valve opening is synchronized with a laser pulseemitted by the laser.